Niessliaceae Kirschst., Annls mycol. 37(1/2): 89 (1939)
MycoBank number: MB 81070; Index Fungorum number: IF 81070; Facesoffungi number: FoF 01126; 13 species.
Saprobic or parasitic on wood, leaves and stems in freshwater and terrestrial habitats, some possibly fungicolous and lichenicolous. Sexual morph: Ascomata perithecial or cleistothecial, yellow, brown, dark brown to black, solitary or gregarious, superficial, erumpent to immersed in a subiculum or crustose stroma, cupulate, globose to subglobose, membranaceous, tuberculate, with or without circinately coiled, lightly pigmented, brown, septate, apical setae, collabent, or collapsing laterally, or not collapsing, papilla present or lacking, when present with periphysate ostiole. Peridium thick, membranaceous, outer layer composed of yellow, light brown or brown cells of textura angularis; inner layer composed of hyaline cells of textura prismatica. Paraphyses-filiform, hyaline, septate, or absent. Asci 8-spored, unitunicate, oblong to clavate, long or short pedicellate, with narrowly discoid, J-, apical ring or ring absent, evanescent at maturity. Ascospores 1–3-seriate, hyaline to brown, ellipsoid to fusiform, slightly curved, aseptate to 1-septate, striate or verrucose, smooth-walled. Asexual morph: Hyphomycetous. Mycelium white to light brown, superficial, effused, thick subiculum. Conidiophores thin-walled, hyaline, unbranched, aseptate, swollen, with a short and distinct collarette, terminating in a single conidium. Phialides straight, smooth. Conidia oval to ellipsoid, aseptate to 1-septate, hyaline, smooth. Coelomycetous, Conidiomata subimmersed, globose to subglobose, dark brown. Peridium thick-walled, wall composed of brown to hyaline cells of textura angularis, becoming hyaline towards inner conidiogenous region. Conidiophores hyaline, subcylindrical, branched apically, 1–2-septate. Conidiogenous cells phialidic, hyaline, fusiform to ellipsoid, straight to curved, tapering towards a subtruncate apex. Conidia oval to ellipsoid, aseptate to 2-septate, hyaline, with guttulate, smooth- walled (adapted from Maharachchikumbura et al. 2016b).
Type genus – Niesslia Auersw.
Notes – Niessliaceae was introduced by Kirschstein (1939) based on superficial, dark, setose perithecial or cleistothecial ascomata, and is typified by Niesslia. Barr (1990b) proposed that members of this family be accepted in a narrow sense and transferred genera from Sphaeriaceae (Müller & von Arx 1962, 1973) and Trichosphaeriaceae, such as Melchioria, Pseudorhynchia and Valetoniella (Barr 1983, Hawksworth et al. 1983, Eriksson & Hawksworth 1990). Samuels & Barr (1997) referred the family to Hypocreales (including Atronectria, Circinoniesslia, Cryptoniesslia, Malmeomyces, Melanopsamma, Miyakeomyces, Myrmaeciella, Niesslia, Paraniesslia, Pseudorhynchia, Trichosphaerella, Taiwanascus, Valetoniella, Valetoniellopsis), based on the short ostiolar periphyses and phialidic conidiogenous cells (Starbäck 1899, Hara 1913, Eriksson & Hawksworth 1991, 1993, Hawksworth et al. 1995, Rossman et al. 1999, Cai & Hyde 2007b, Etayo & Sancho 2008). The placement of Niessliaceae in the Hypocreales is supported by molecular data and includes Eucasphaeria, Hyaloseta, Myrtacremonium, Niesslia, Rosasphaeria, Trichosphaerella and Valetoniellopsis (Tang et al. 2007, Jaklitsch & Voglmayr 2012, Lombard et al. 2015, Crous et al. 2016a, 2017b). Many genera included in Niessliaceae lack sequence data and several are monotypic and thus recollection and sequence data is needed.